If you create something like this to use in your classroom, pay attention to a few things (based on my personal experience):

- include at least one example of each "kind"of noun (i.e. person, place, thing, animal)

- the output of the machine should not only show items in groups of 2s (in the chart above: 2 flowers, 3 clouds, 4 houses, etc). I've once made that mistake and had a couple of students misunderstanding that the plural only referred to groups of 2s.

- use words that have different ending sounds. Again, I had students creating their own "add -s" rule based on the ending sound.

When creating anchor charts for plural nouns, you might also want to use a different chart for each case/rule.

Here's one on the "add -ES" rule for nouns ending in S/SH/CH/X/Z/SS:

And another one on the "drop and add" rule for nouns ending in Y and nouns ending in F/FE:

You might want to add that the "y" rule is only valid for words ending in -y preceded by a consonant. So, nouns like "boy", "bay", "toy" only need -s to become plural.

And there's the plural nouns "snapshot" anchor chart, where the most common plural cases are all in the same chart:

Of course, what you'll end up adding to your anchor charts will vary according to what your students need to know and what you want to teach, but I hope you now have some anchor chart ideas to inspire you.